1. Field of Invention
The invention relates to methods and apparatuses for the remediation of contaminated water and/or soil and, in particular, to the reduction of the concentration of organic compounds in water and/or soil.
2. Discussion of Related Art
Both State and Federal governments have issued regulations governing hazardous organic and inorganic contaminants in the environment. Subsurface soil and groundwater contamination with organic and inorganic contaminants has been a concern since the 1970's. Action levels and clean-up standards have been promulgated by both State and Federal government for numerous organic and inorganic contaminants.
Regulated organic contaminants in the subsurface environment include, but are not limited to: polychlorinated biphenyls (PCBs); chlorinated volatile organic compounds (CVOCs) such as tetrachloroethene (PCE), trichloroethene (TCE), trichloroethane (TCA), dichloroethene (DCE), vinyl chloride; fuel constituents such as benzene, ethylbenzene, toluene, xylene, methyl tert butyl ether (MTBE), tertiary butyl alcohol (TBA), polynuclear aromatic hydrocarbons (PAHs), ethylene dibromide (EDB); pesticides such as (but not limited to) DDT; and herbicides such as (but not limited to) silvex. Regulated inorganic contaminants in the subsurface environment include, but are not limited to: heavy metals, such as lead, arsenic, chromium, mercury, silver. State and Federal regulations that govern these subsurface contaminants outline a protocol for subsurface investigation to identify the extent of contamination, identification of the human health and ecological risk posed by the contaminants, development of remedial action alternatives for reducing or eliminating any significant risk posed by the contaminants, and selection and implementation of remedial measures to achieve the remediation goals.
In situ (ISCO) or ex situ (ESCO) chemical oxidation technology has emerged as a prominent remedial measure due to its cost-effectiveness and timeliness in achieving remediation goals. ISCO technology can be used alone or in combination with other complementary technologies, such as soil vapor extraction (SVE) for removal of volatile organic compounds from the unsaturated zone, multi-phase extraction for removal of organic contaminant from the unsaturated and saturated zones, or vertical recirculation systems in the saturated zone.
The literature regarding ISCO or ESCO reports the use of a strong oxidizing agent to treat contaminated soil and water by chemically degrading recalcitrant and hazardous chemicals. Such oxidants include hydrogen peroxide, Fenton's reagent, ozone, permanganate, persulfates, and other peroxygens.